I'm inclined to agree that an after-boot firmware
interface is unnecessary; I don't see the point in keeping
OpenFirmware alive after the system is booted -- but
OpenFirmware does seem to be a good choice as the
boot firmware. It's a lot smaller and easier to
deal with than Linux-as-bootloader, which we were using
before. We only have 1MiB of NOR flash to boot from, and
L-A-B was too big. OpenFirmware does the job very nicely.

It's also been a godsend when we've been bringing up the
hardware. We've designed entirely new chips for OLPC, and
have been working with FPGA versions of them during their
lifecycle (the final build with the ASICs of everything
should happen this week). Debugging that hardware with
OpenFirmware is like magic -- especially if you watch Mitch
doing it :)